158 
GEOLOGY OF NORTH CAROLINA. 
not only a stratum of earth and pebbles small and large, but in one part 
of it many huge rounded and polished, yellowish quartz bowlders, some 
of them weighing 2 and 3 towns, a true bowlder clay. 
On the table land beyond the Blue Ridge these drift beds are quite as 
abundant and well characterized. The cut at Swannanoa gap is a good ex- 
ample. This drift bed begins almost at the summit, within one or two hun- 
dred yards, and there are frequent additional examples on the road to Ashe- 
ville, where such an accumulation may be fonnd on the summit of the 
highest knob overlooking the town and not less than 300 feet above the 
French Broad, a mile distant. This bed has long furnished cobblestones 
for the pavements of the town. Some of these stones are peculiar, as the 
heavy black compact tourmaline pebbles, and these have been traced to 
their source in a vein on a foothill of the mountains 6 miles above, to- 
wards the Blue Ridge. Similar accumulations are fonnd along the valley 
of the French Broad to Tennessee, on the slopes and benches of the moun- 
tains on either hand, sometimes to a height of one or two hundred feet, 
generally in the form of terraces. But along the slopes and benches among 
the mountain ranges are frequent accumulations of earth and slightly worn 
fragments of quartz and other hard rocks, which it is difficult to account 
for except on the supposition of an intensity of cold and an accumulation 
of ice and an exaggeration of the amount of rainfall which are not easy 
to conceive. 
It is not possible to give a just impression of many of the phenomena 
above described without the help of illustrative diagrams, and it is pro- 
posed to give in the next volume some of the numerous sections which 
have been taken of these Quaternary strata in all parts of the State. 
Glaciers.— There is no evidence of the former existence of glaciers in 
this State, unless of the most local and limited character ; but there is 
strong evidence of their non-existence over nearly the whole area of the 
State, conspicuously in the piedmont and mountain regions, in the mode 
of occurrence of the till and pebble beds already described. These beds 
adjust themselves accurately to all the inequalities of surfaces, which are 
composed of the irregularly eroded edges of foliated, or bedded rocks, of 
variable disintegrability ; whereas the whole surface would have been 
evenly planed, or smoothed and rounded, (if not polished and grooved 
and striated), as in Glacial latitudes; and the total absence of this latter 
sort of evidence may be at least taken as confirmation of the conclusion 
reached on other grounds. 
But the conclusion seems to be inevitable that, in the modified sense, 
which is obvious from the preceding descriptions, the whole middle and 
western sections of the State have been extensively and profoundly gla- 
